1. Field of the Invention
The present invention relates to a panel and a method for fabricating the same. More particularly, the present invention relates to a touch panel and a method for fabricating the same.
2. Description of Related Art
According to different sensing principles, touch panels may be categorized into resistant touch panels, capacitive touch panels, optical touch panels, sonic wave touch panels, and electromagnetic touch panels etc. Among the touch panels, the projective capacitive touch panels have drawn much attention due to rapid growth in smartphone sales.
Typically, the projective capacitive touch panels may be categorized into island-type and via-type projective capacitive touch panels according to how a passivation layer is arranged between conductive layers. FIG. 1A is a schematic top view showing a conventional island-type projective capacitive touch panel. FIG. 1B and FIG. 1C are schematic cross-sectional views respectively along lines I-I′ and II-II′ of FIG. 1A. Referring to FIG. 1A through FIG. 1C, a projective capacitive touch panel 100a includes a substrate 102, buffer layers 104a and 104b, a plurality of first sensing series 110, a plurality of second sensing series 120, a passivation layer 130 and a covering layer 140 serving to insulate the first sensing series 110 from the second sensing series 120. Each of the first sensing series 110 includes a plurality of first sensing pads 112 and a plurality of first bridging lines 114 located among the first sensing pads 112. Each of the second sensing series 120 includes a plurality of second sensing pads 122 and a plurality of second bridging lines 124 located among the second sensing pads 122.
In the island-type projective capacitive touch panel 100a illustrated in FIG. 1A through FIG. 1C, the passivation layer 130 is patterned as island-shaped and arranged between the second sensing pads 122 and the first bridging lines 114. Thus, when a material of the passivation layer 130 is similar to a material of the buffer layers 104a and 104b, the buffer layers 104a and 104b serving as optical index-match layers are also removed in a fabricating process for patterning the passivation layer 130, which results in reduced adjustment flexibility for optical characteristics of the projective capacitive touch panel 100a. 
FIG. 2A is a schematic top view showing a conventional via-type projective capacitive touch panel. FIG. 2B and FIG. 2C are schematic cross-sectional view respectively along lines I-I′ and II-II′ of FIG. 2A. Referring to FIG. 2A through FIG. 2C, a projective capacitive touch panel 100b has elements that are substantially identical to those of the island-type projective capacitive touch panel 100a, and a major difference therebetween lies in the passivation layer 130 covers the first bridging lines 114, and the first sensing pads 112 are electrically connected with the first bridging lines 114 through via holes 132 in the passivation layer 130. Since the passivation layer 130 entirely covers the substrate 102, optical stability of the via-type projective capacitive touch panel 100b is easily influenced by a thickness of the passivation layer 130. As a result, the optical stability of the via-type projective capacitive touch panel 100b may be even worse than that of the island-type projective capacitive touch panel 100a. 
Accordingly, the way by which the passivation layer is arranged would influence optical characteristics of the projective capacitive touch panel. Therefore, how to design a projective capacitive touch panel with good optical characteristics is a major subject to be worked on by technicians and research and development personnel in the field of the present invention.